Sliding closures on the spout of containers for molten metal are known in many different embodiments, these basically possibly being sliding closures with a linearly adjustable slider unit (see e.g. EP-A-0 875 320) or rotary sliding closures (see e.g. CH-A-649 149). As is well known, the fire-resistant components of these sliding closures, in particular the closure plates, but also their spout covers and the covers on the container outlet, are subjected to heavy wear and tear and must from time to time be inspected and if need be be changed. The emptied container, e.g. a so-called pan, is brought together with the sliding closure to a maintenance point, a so-called pan position, where the horizontally positioned pan is cleaned, the sliding closure is opened, and the individual components which if need be are to be replaced, are dismantled using appropriate tools, cleaning operations are performed and then the components or the replacement parts for the latter are assembled again. In the specialist jargon this maintenance is also called preparation. These maintenance and preparation operations must be carried out manually. The way in which the sliding closure is opened and the means for opening and closing the sliding closure depend upon the design of the respective closure.
A sliding closure provided with a linearly adjustable slider unit is—as described for example in EP-A-0 875 320—actuated by means of a piston/cylinder unit that can be mounted on the sliding closure in order to open or close the pouring channel. Unlike the sliding closure, the piston/cylinder unit is not always attached to the pan, but it remains—once again removed from the sliding closure—on the pouring unit or in the pan position where the opening and closure of the pouring channel is to take place. When mounting on the sliding closure, the cylinder is inserted into a retainer on the slider housing and held securely in position in the latter while the drive rod is coupled to the slider unit. The slider unit's stroke for opening and closing the pouring channel is restricted by a stroke limitation bolt. If the closure plates are to be changed, the stroke limitation bolt is removed and the slider unit pushed out over the one limit position after which it is released from the slider housing and pivoted out in relation to the latter, and the closure plates are made accessible.
With a changing device according to publication JP-A-10263796 for changing a fire-resistant material in a sliding closure mounted on a steel pan, a stage moveable on rails and a robot disposed on the latter are provided which can be equipped with various tools. Moreover, slider plates and cover magazines are provided in addition to the robot on this stage.
The object which forms the basis of the present invention is to provide an arrangement of the type specified at the start with which the maintenance and preparation operations can be substantially facilitated.
This object is achieved according to the invention by an arrangement wherein a robot is able to automatically detect an exact position of a container or of a sliding closure, means for opening and closing the sliding closure are provided which comprise a piston/cylinder unit which can be brought by the robot from a repository to the sliding closure and that are mountable on the sliding closure and connectable to a pressure source, and wherein the robot can, depending on the condition of individual components that might need to be replaced, grip tools or replacement parts from the magazines surrounding it and perform cleaning operations, dismantle components and replace or reinstall the same.
Further preferred embodiments of the arrangement according to the invention form the subject matter of the dependent claims.
Advantages are obtained with this arrangement according to the invention—on the one hand that fewer staff members are needed to carry out the maintenance and preparation operations, which reduces costs, it also being guaranteed that the operations proceed without any error. Moreover, there is a higher level of work safety then with the conventional preparations because the operators no longer need to carry out work directly in front of the hot pan.